Craftsman DLT2000 w/20hp Kohler retrofit

If anyone could help me I would appreciate it.
Im looking for an engine for my moms mower (which I havent even seen yet) and is a Craftsman DLT2000. It has a Kohler Command 20hp twin and the engine has low oil pressure. I dont want to rebuild the engine just yet even though it only has 10lbs oil pressure andit is in the middle of growing season.
My question is can I retrofit this engine with a B&S to get her through the season. The commands are a little pricey at 1000+ and she wants to get a cub 1050 next year so a used B&S for three or four would do the trick.
I thank all of you in advance for your help.

With enough welding and duct tape you can make anything work. The thing to check would be bolt pattern. I guess if it is different a adaptor plate can be made. The other area is the electrical. Also might have to buy new pullys if the shaft diamater between the motors are not the same.

It might be easier to look for like type mower at a parts shop or any place that deals with small engine or salvage yards. Other than the low oil preasure are there any other issues?